Bruce,
Thats it in a nutshell. I spent the winter day dreaming, scheming, conceptualizing, refining what I actually want, and then ended up with a plan that is now rapidly devolving. But with that said, The basic plan is still sorta there . . . well of course that depends on which plan we are talking about (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif). It looks nothing like the very first plan for the space. The plan helped me work out what I wanted. Now there is reality and making it fit.
On that note. Here is an example of the first bought with reality verses plan. So I wanted a walkway between the apex of the reversing loop and the bench work against the house. I even modified the bench work to facilitate it. The space is 12.5 wide and on the computer this gave me roughly a 28" walkway between the two.
Then you can see in the picture above I built the entire reversing loop in my drive way to what actually works without going under an 8’ diameter curve. Well yesterday evening I was rewarded with the realization that the reversing loop, by the time I made the beam wall and stayed clear of that by 6", ended up actually a bit under the bench. So that meant I would need to build a step up onto the raised portion of the layout with a path along the bench and then a step down on the other side. This also meant i need to lower it some in order to make it so I could climb onto it.
Here is the result. The track is 12" under the the 2X4 stringers of the bench. The train can pass under it. To climb back up it will require a near 3% grade. The steps are built out of 2X8 so real vertical height is 22 1/2 inches. They are box construction so they will act also as a retaining wall. I will fill them with the same gravel as the paths. I built the track to run right through it and it acts as a support for the ladder. Then I needed a vertical wall to the left of the steps so that I could still open up the cabinet door. The path to the left is 31" wide and allows access to the yard. The vertical wall is 2X8 with 4X4 posted cemented into the ground. From the left side of this wall I will follow the curve of the track with a rock wall. There will be a matching set of stairs (half done in my garage) that will step down on the other side of the loop. The big down side to this is the 5 way switch will require a person to kneel down to operate. Not a deal breaker but that would have been nice to have waist high.
Edited to say: One concern I have is walking on the track. With it being in the middle of the step it will get stepped on. Being aluminum I don’t want it bent. So I have an idea, the PVC boards have a decent wood grain texture, so I am thinking of making strips out of it that are .250 (code 250) thick and whatever width and then laying them on the ties like they do on crossings and bridges. Painted brown they should look pretty good and hold up and protect the track. We are a ways off from that but its a solution to the problem.